Counting the amount of occurrences in a list of tuples

Question

I am fairly new to python, but I haven't been able to find a solution to my problem anywhere. I want to count the occurrences of a string inside a list of tuples. Here is the list of tuples: ``` list1 = [ ('12392', 'some string', 'some other string'), ('12392', 'some new string', 'some other string'), ('7862', None, 'some other string') ] ``` I've tried this but it just prints 0 ``` for entry in list1: print list1.count(entry[0]) ``` As the same ID occurs twice in the list, this should return: ``` 2 1 ``` I also tried to increment a counter for each occurrence of the same ID but couldn't quite grasp how to write it. *EDIT: Using Eumiro's awesome answer. I just realized that I didn't explain the whole problem. I actually need the total amount of entries which has a value more than 1. But if I try doing: ``` for name, value in list1: if value > 1: print value ``` I get this error: ``` ValueError: Too many values to unpack ```

Accepted Answer

Maybe `collections.Counter` could solve your problem:

```
from collections import Counter
Counter(elem[0] for elem in list1)
```

returns

```
Counter({'12392': 2, '7862': 1})
```

It is fast since it iterates over your list just once. You iterate over entries and then try to get a count of these entries within your list. That cannot be done with `.count`, but might be done as follows:

```
for entry in list1:
    print(sum(1 for elem in list1 if elem[0] == entry[0]))
```

But seriously, have a look at `collections.Counter`.

EDIT: I actually need the total amount of entries which has a value more than 1.

You can still use the `Counter`:

```
c = Counter(elem[0] for elem in list1)
sum(v for k, v in c.iteritems() if v > 1)
```

returns `2`, i.e. the sum of counts that are higher than 1.

Counting the amount of occurrences in a list of tuples

Solution

Problem